Electrical transformer



C. H. THORDARSON.

ELECTRICAL TRANSFORMER.

APPHCATION FILED NOV. 6,1916.

Patented May 17, 1921.

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c. H. THORDARSON ELECTRICAL TRANSFORMER.

APPLICATION FILED NOV-631916.

Patented May 17, 1921.

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UNITED STATES PATENT OFFICE.

CHESTER H. THORDARSON, OF CHICAGO, ILLINOIS.

ELECTRICAL TRANSFORMER.

Application filed November 6, 1916.

Tc all whom it may concern:

Be it known that I, CHESTER H. THonoAR- soN, a citizen of the United States, residlng at Chicago, in the county of Cook and State of Illinois, have invented certain Improvements in Electrical Transformers; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in electrical transformers of the closed core type and the invention refers more specifically to improvements designed to vary. the magnetic flux of the transformer core and thereby vary the input of the transformer to correspondingly vary its output and to improve means to vary the adjustable factor of the transformer and lock it in adjustment. The invention relates also to other improvements in transformers, and the invention consists in the combinations and arrangements of the parts shown in the drawings and described in the specification and is pointed out in the annexed claims.

In the drawings:

Figure l is a side elevation of a transformer embodying my invention.

Fig. 2 is a section on the line 22 of Fig. 1.

Fig. 3 is a section on the line 33 of Fig. 1.

Fig. at is a diagram illustrating the elements of the core or magnetic circuit.

Fig. 5 is a plan view showing a detail of the high tension winding protecting ring.

Fig. 6 is a section on the line 66 of-Fig. 5.

Figs. 7 and 8 are details of an expanding supporting ring for the high tension coil.

Fig. 9 is a section on the line 9-9 of Fig. 1.

Fig. 10 is a section on the line 10-10 of Fig. 9.

Fig. 11 is a diagram showing a modification of the core or magnetic circuit.

As shown in the drawings, the core or magnetic circuit comprises upper and lower yokes 10, 11 respectively, and upright side members 12, 13. Said core members are of laminated construction following the usual practice. The abutting edges of the laminae of the core members are of irregular or saw-tooth contour as in the construction shown in my pending application for U. S. .Letters Patent, Serial No. 75,969, filed the Specification of Letters Patent.

Patented May 17, 1921.

Serial No. 129,779.

3rd day of February, 1916, the purpose of wh ch arrangement is to improve the magnetic JOlIltS between the abutting parts. The low tension winding 1 1 is mounted on the lower yoke member 11 of the core and the high tension winding 15 is mounted on the upper yoke member 10 thereof.

In accordance with my invention the magnetlc c rcult comprises, in addition to the closed circuit core structure, an external laminated shunt member 16 which, as shown in Fig. 4, 1s arranged below the low tension winding yoke of the core and abuts at its upper edge near one end thereof against the lower end of the side member 13 of the core, which latter extends beyond the side member 12. Said shunt member extends at its other end beyond the other side member 12. The shunt member is separated from the lower end of the side member 12, WhlCh latter extends slightly below the yoke 11, to provlde an air gap which, when fully opened, lncreases the magnetic reluctance between the shunt member and the side mem-- ber 12'to such extent that the magnetic flux is substantially within the core, consisting of the members 10, 11, 12 and 13. The w1dth of said air gap is regulated by means of a slldlng member or tongue 18, preferably of laminated construction, which has a flat bottom face 19 that fits fiat on the upper face of the extended end of the laminated shunt member 16 and is provided with an upwardly facing inclined or wedge face 20 which cooperates with a corresponding, downwardly facing inclined end face 21 of the side member 12 of the core. When said tongue 18 is moved inwardly against the lower inclined end face of the side member 12 the air gap between the shunt member and said member 12 is closed. In this adjustment of the parts, the shunt member 16 shunts a part of the magnetic flux from the low tension winding yoke 11 of the core so that only a portion of the flux developed in the core passes through said high tension winding yoke to magnetize the high tension winding, depending upon the cross section of the shunt member 16 relatively to the yoke 11 and the counter magnetic flux in the core, due to the action of the high tension winding thereon. By sliding said tongue 18 outwardly away from the inclined end face 21 of the side member 12 an air gap of 32, which engage over greater or less width is interposed between the shunt member and the member 12, so

as to more or less increase the magnetic reluctance to the flux flowing through the shunt member, and to more or less decrease the input to the transformer, with a corresponding variation oftheroutput of the transformer. The greater the air gap between the shunt member and the core member 12, the greater will be the proportion of the magnetic flux passing through the core proper, with the result that the output of the transformer is increased. Thus the input may be varied by adjusting said shding tongue end face of the core member 12 so as to vary the output of the transformer as desired.

The shunt member of the core is supported between angle base plates 24 by means of clamping bolts 25. The side members 12 and 13 of the core are in like manner clamped between angle bars 26, 27 by means of clamping bolts 28, 29 and overlap at their lower ends the webs of the plates The openings in the plates 26 through WhlCll the upper bolts 28 extend are elongated transversely of the plates. The plates 26 on the side of the transformer atwhich the air gap occurs between the shunt member 16 and the core member 12 are made of brass or other non-magnetic material to avoid closing the air gap at this point. The upper ends of the side plates 26, 27 are held together by means of tie bars 31, as shown best 1n Fig. 3, which extend horizontally between the said plates, alongside the upper yoke 10 and are provided at their ends with hooks the edges of the angle frame members 26, 27. The upright laminated members of the core are forced into contact with the yokes 10 and 11 by means of clamping bolts 35, 36, the headed ends of which extend through the lateral flanges of the frame members and the other ends of which extend through tie bars 37, 38 which lie along the outer edges of the laminated core exterior to the side frame members, and nuts 40, 41 acting against said tie bars act to force the laminae of said side member inwardly against those of the yoke members 10, 11.

Referring now to the means for adjusting-the slidable tapered tongue 18 relatively to the external shunt member 16 and to the core and for locking the tongue in adjusted positions, a practical method of adjustment is shown in Figs. 1, 9 and 10 and is made as follows 45, 45 designate plates which are fitted to the sides of the laminated tongue member and are clamped thereto by one or more clamping bolts 46. Said plates are toothed on their upper edges to provide racks 47, the ends of which, as herein shown, are in the plane of the upper face of the tongue.

18 toward and from the inclined 48 designates a horizontal shaft which lies transversely over said tongue and is 1'0- tatively mounted at its ends in hearings in vertical plates 49, made of brass or other non-magnetic material, which are attached to the core structure in any suitable manner, as by means of a bolt 50 and extend at their upper ends above the plane of the upper face of the tongue. Fixed to the said shaft opposite to the racks 47, and meshin with said racks, are gear sectors 51; Sai shaft is provided at one of its ends, exterior to the adjacent plate 49, with a crank arm 52 by which the shaft is rotated to thereby rotate said gear sectors 51. Rotation of the shaft 48 has the effect to cause the tongue 18 to slide inwardly or outwardly on the external shunt member, depending upon the di rection of the rotation of the shaft. 'Said tongue is locked in adjusted positions by means of an eccentric locking sleeve 55 which is loosely mounted on the shaft 48 and is adapted to engage the upper face of the tongue. Said locking sleeve 55 is provided with a hand piece 56 by which it may be rotated about the axis of the shaft 48. When the sleeve is in the position shown in Fig. 10, with its eccentric portion between the shaft and the tongue, it grips the tongue to lock it in a fixed position relatively to the co-actlng tapered face 21 of the core. When the tongue is to be endwise adjusted to vary the width of the air gap, the hand piece 56 is thrown upwardly to release the sleeve from the surface of the tongue, whereupon the tongue is free to be shifted.

One of the side clamping plates of the tongue is graduated, as shown in Fig. 1, to provide a scale 57, graduated as to input, which is read from the outer vertical edge of the adjacent plate 49 so as to permit of close graduations of adjustment of the air gap and consequent output energy of the transformer.

An important advantage of the construction described is accuracy of adjustment of the transformer to predetermined conditions of input and output and the accurate maintenance of a given adjustment. A further advantage of said construction is the freedom of the regulating or adjusting parts from rattling under vibration of the transformer, resulting in a noiseless transformer under all operating conditions. It will be noted that the magnetic pullexerted on the tongue is in a direction to tighten the looking device, thus enhancing the positiveness of the lock and maintaining the parts free from rattling and consequent maladjustment. A further advantage of said construction is the extreme simplicity of the adjusting devices and their ready incorporation in a transformer and the low cost of manufacture and assembly.

The high tension coil 15 is of ring-like disk form and is preferably wound with a plurality of parallel turns of insulated wires, the several turns of which are convcniently insulated from each other bylthe insulating method shown in my prior S. Letters Patent No. 889,838, granted on the 3rd day of March, 1908. The said coil is insulated from the upper yoke 10 by a suitable insulating sleeve embracing an outer heavy insulating ring or sheet 58. The coil is interior-1y supported by an open expansible metal ring 60, which is in electrical contact with the inner turns of the coil and said ring is expanded against the interior of the coil by means of a wedge 61 made of insulating material, having side grooves 62 (Figs. 7 and 8) which engage the adjacent end edges of the expansible ring 60. Said end edges of the ring and the bottoms of the grooves are'tapered so that when the wedge is driven inwardly between the ends of the open supporting ring the ring is expanded outwardly closely against the interior of the coil.

The high tension coil 15 is supported and protected at its periphery by a flat metal band 63 which is formed to almost entirely encircle the coil and is clamped together at its ends to effect a confining pressure on the coil. The side edges of said plate 63 are folded inwardly to inclose reinforcing wires (31. the effect of which is to eliminate corona and which in turn reduces the liability of flashing over the surface of the coil. The said band 63 is herein shown as clamped on the coil in the following manner.

The reinforcing wires 64 are made of a single length of wire bent between its ends in general U-shaped formation. The free ends of the wire 64 at one end of the plate extend through openings in a terminal block 65 and are riveted thereto at 66. At the other end of the band the transverse member 67 of the U-shaped reinforced wire extends transversely across the plate and is engaged by a clamping member 68 that is fixed by screws 69 to the terminal block, the clamping plate being so arranged as to effect a clamping pressure on the bail or closed portion of the reinforcing wire when the screws 69 are tightened. The said closed portion 66 of the wire is insulated from the clamping plate 68 by an insulating member 70.

One of the terminals 72 of the high tension coil is mounted on the block 65 and its connection with the outer end of the high tension coil is through the protecting band 63. The inner end of the high tension coil is connected to a terminal 74 which is mounted on the end of a metal arm 75 which extends from the inner portion of the coil outwardly to one side thereof and is attached to the ring 60. The terminal arm 7 5 is extended through the coil to the other side thereof and is turned upwardly at 76 to form between the same and the terminalblock 65 a spark gap of such width as to protect the high tension winding.

The general construction of the transformer, aside from the external magnet shunt, is extremely simple and economical in its construction and results in a very durable and rugged construction. The windings are treated to with-stand the elements,- so that the transformer is capable of withstanding exposure without endangering its eflicienc In Fig. 11 is shown a form of transformer, employing the external magnetic shunt feature of the invention, which is more particularly adapted for high potential transformers which are immersed in an insulating and cooling liquid. In this type of transformer it is desirable that the shunt regulating tongue be located at the top of the transformer above the body of the liquid. To this end the external magnetic V ployed for guiding the tongue toward and away from the inclined face 83 and for locking the tongue in adjusted positions.

The arrangement of the shunt member adjacent to the low winding yoke is advantageous inasmuch as said shunt member may be more compactly assembled in the transformer and the assembled structure maintained symmetrical than if associated with the high tension winding yoke or other member of the core. The frame is built of formed sheet steel and brass which renders the construction nonbreakable and greatly reduces its weight. 1

It is to be understood that the invention is capable of considerable structural variations without departure from the spirit thereof and that the foregoing description of the details showing one embodiment of the invention is not intended to be limiting, but it is the intent to claim all of inherent novelty shown in the drawings and described in the specification. Reference herein made to a transformer of the closed core type is not necessarily intended to specify a completely closed core but includes core constructions which in themselves may not be completely closed.

The coil structure herein described is not herein claimed but said structure is disclosed and claimed in another application I the tapered surface of' the gap, and locking means to lock said element in fixed position in the gap.

2. In a transformer, a magnetic circuit provided with an air gap formed by a sup-- porting surface and a tapered surface, a magnetic element movable along said supporting surface to vary the width of said gap, rack and pinion means to actuate said element, and locking means for said element cooperating with the magnetic pull of the circuit to hold said element from vibration.

3. In a transformer, a magnetic circuit provided with an air gap formed by a supporting surface and a tapered surface, a magnetic element movable along said supporting surface to vary the width of said gap, rack and pinion means to actuate said element, and cam means to lock said element in adjusted positions.

4:. In a transformer, a magnetic circuit provided with a shunt member having an air gap formed by a supporting surface and a tapered surface, a magnetic element slidable along said supporting surface to vary the width of said gap, rack and pinion means to actuate said element and a rotative cam lock acting against said element.

5. In a transformer, a magnetic circuit provided with a shunt member having an air gap formed by a supporting surface and a tapered surface, a magnetic element slidable along said supportlng surface to vary the width of said gap and subject to the magnetic pull of said circuit tending to hold said element in looking position, rack and pinion means to actuate said element and a rotative cam lock acting against said element.

6. A transformer comprising a magnetic circuit, a magnetic shunt member provided with an air gap formed by relatively inclined surfaces, a magnetic element movable into and out of said gap, and means to actuate said element, said element having faces inclined at the same angle as said surfaces and slidable along one surface.

7. A transformer comprising a magnetic circuit provided with an air-gap formed by a supporting surface and a surface inclined thereto, a magnetic element having faces relatively inclined at the same angle as said surfaces and slidable on said supporting surface, means to shift said member toward and from said inclined surface, and means to lock it in adjusted position.

8. The combination with a transformer comprising a core and high and low tension windings, of a magnetic shunt member provided with an air gap, a movable magnetic member controlling said air gap, rack and gear mechanism to actuate the movable member, and locking means for the movable member eccentric to said gear mechanism.

9. A transformer comprising a core, high and low tension windings thereon, a magnetic shunt member provided with an air gap, a magnetic tongue slidable into and out of said gap-to variably close the same, a rack bar fixed to-said tongue, a rock shaft extending across said tongue, a gear carried by the shaft and meshing with said rack, and tongue locking means associated with the shaft.

10. A transformer comprising a core, high and low tension windings thereon, a magnetic shunt member provided with an air gap, a magnetic tongue slidable into and out of said gap to variably close the same, a rack bar fixed. to said tongue, a rock shaft extending across said tongue, a gear carried by the shaft and meshing with said rack, and an eccentric locking sleeve rotatively mountedon said shaft for locking contact with said tongue.

11. A transformer comprising a core, high and low tension windings thereon, a magnetic shunt member magnetically joined at one end to the core and separated at its other end from the core by an air gap having a straight face formed on said shunt member and an opposing inclined face formed on the core, a magnetic tongue slidable on said straight face of the air gap and having an oblique face to oppose the inclined face of the 'core, means to slide said tongue into and out of said gap, and locking means for said tongue.

12. In a transformer a core comprising laminated yokes and laminated side pieces, high and low tension windings on said core, one side core piece extending beyond the low tension winding yoke, a laminated external magnetic shunt member joined to said side piece and provided with an air gap, means to variably close said air gap, clamping plates fitted to the shunt member and clamped thereto,side clamping plates fitted to the side core pieces and clamped thereto and attached to the shunt member clamping plates and clamping means between the side clamping plates and said laminated core side pieces to force said core side pieces against the yokes.

13. In a transformer a core comprising laminated yokes and laminated side pieces, high and low tension windings on said core, one side core piece extending beyond the low tension Winding yoke, a laminated external magnetic shunt member joined to said side piece and provided with an air gap, means to variably close said air gap, clamping plates fitted to the shunt member and clamped thereto, side clamping plates fitted 130 to the side core pieces and clamped thereto and attached at one end of the transformer to the shunt member clamping plates, a tie bar extending between and locked to the other ends of the sideplates, and clamping means for forcing the side core pieces against the yokes.

14. In a transformer a core comprising laminated yokes and laminated side pieces, high and low tension windings on said core, one side core piece extending beyond the low tension winding yoke, a laminated external magnetic shunt member joined to said side piece and provided with an air gap, means to variably close said air gap, clamping plates fitted to the shunt member an clamped thereto, flanged side clamping plates fitted to the side core pieces and clamped thereto and attached at one end of the transformer to the shunt member clamping plates, tie bars extending between and locked to the other ends of the side plates and lying alongside the adjacent yoke, and clamping means anchored to the flanged side plates and bearin against the edges of the side core pieces or forcing said side core pieces against the yokes.

15. In a transformer, a core comprising laminated yokes and laminated side pieces, high and low tension windings on said cores, one side core piece extending beyond the low tension winding yoke, a laminated external shunt member adjacent to the latter yoke and abutting at one end against one of the core side pieces and extending at its other end beyond said last mentioned yoke and spaced from the other side core piece by an air gap, a magnetic tongue slidable on said shunt member to variably close said air gap, clamping plates fitted to and clamped upon said shunt member and said side core pieces, means to actuate said tongue and means to lock the tongue in adjusted position. 7

16. In a transformer, a core comprising laminated yokes and laminated side pieces, high and low tension windings on said cores, one core side piece extending beyond the low tension winding yoke, a laminated external shunt member adjacent to the latter oke and abutting at one end a ainst one o the core side pieces and exten ing at its other end beyond said last mentioned yoke and spaced from the other core side piece by an air gap, a magnetic tongue slidable on said shunt member to "ariably close said air gap, clamping plates fitted to and clamped upon said shunt member and said side core pieces, a rack on said tongue, plates attached to the shunt member clamping plates at the sides of the tongue, a rock shaft extending across the tongue, and gears fixed to said shaft and meshing with said rack.

17. In a transformer, a core comprising laminated yokes and laminated side pieces, high and low tension windings on said core, one core side piece extending beyond the low d tension winding yoke, alaminated external shunt member adjacent to the latter yoke and abutting at one end against one of the core side pieces and extending at its other end beyond said last mentioned yoke and spaced from the other core side piece by an air gap, a magnetic tongue slidable on said shunt member to variably close said air gap, clamping plates fitted to and clamped upon said shunt member and said side core pieces, a rack on said tongue, plates attached to the shunt member clamping plates at the sides of the tongue, a rock shaft extending across the tongue, gears fixed to said shaft and meshing with said rack, and a locking eccen' trio rotatively mounted on said shaft and engaging said tongue.

18. A magnetic circuit having an air gap formed by a supporting surface and a tapered surface, a magnetic element movable along said supporting surface, to vary the width of the gap, said magnetic element being subject to the pull of the magnetic circuit tending to pull it into, and reduce the width of, the air gap, and eccentric locklng means cooperating with said magnetic element.

In witness that I claim the foregoing as my invention, I hereunto aflix my slgnature in the presence of two subscribing witnesses at Chicago, Illinois, on November 18th, 1916.

CHESTER H. THORDARSON.

Witnesses:

WILLIAM L. HALL, M. KENNEDY. 

